1. Field of the Invention
This invention relates to a chemical analysis apparatus for applying a substance to be measured to a chemical analysis slide, i.e. a slide type chemical analysis device, provided with a reagent layer, maintaining the chemical analysis slide at a predetermined temperature (i.e. carrying out incubation) for a predetermined time, and then optically measuring the degree of color formation in the chemical analysis slide for quantitative analysis of the substance to be measured.
2. Description of the Prior Art
Quantitative analysis of a specific chemical constituent in a liquid sample is generally carried out for various industrial purposes. Particularly, it is very important in biochemical and clinical categories to quantitatively analyze chemical constituents or physical constituents in body fluid such as blood or urine.
In recent years, as disclosed in, for example, Japanese Patent Publication No. 53(1978)-21677 and Japanese Unexamined Patent Publication No. 55(1980)-164356, there has been developed and put into practice a dry type chemical analysis slide for quantitatively analyzing a specific chemical constituent or a specific physical constituent contained in a sample solution simply by applying a droplet of the sample solution. With the chemical analysis slide, it is possible to analyze a sample solution more simply and more quickly than when the conventional wet type analysis method is used. Therefore, the use of the chemical analysis slide is desirable particularly in medical organizations, research laboratories, or the like where many samples are to be analyzed.
In order to analyze a chemical constituent or the like contained in a sample solution by use of the chemical analysis slide, a measured amount of the sample solution is put on the chemical analysis slide and is maintained at a predetermined temperature (i.e. Incubated) for a predetermined time in an incubator to cause a color reaction, the chemical analysis slide is exposed to measuring light having a wavelength selected in advance in accordance with the combination of the substance to be measured with a reagent contained in the reagent layer of the chemical analysis slide, and the optical density of the light reflected by the chemical analysis slide is measured. In this manner, it is possible to achieve quantitative analysis of the substance to be measured such as the chemical constituents or the like.
Various chemical analysis apparatuses have heretofore been proposed for carrying out quantitative analysis of a substance to be measured in the manner as mentioned above. In general, the chemical analysis apparatus is provided with an incubator having a slide housing compartment for carrying out incubation. The temperature in the incubator is maintained at a predetermined value by a temperature adjustment means composed of a heater, a temperature sensor, a heater operation control circuit and the like. Also, in the case where the incubator is provided, the slide housing compartment is generally provided with a read-out opening, and a read-out head for emitting the measuring light to the reagent layer of the chemical analysis slide and measuring the optical density of the light reflected by the reagent layer is disposed to stand facing the reagent layer of the chemical analysis slide in the housing compartment via the read-out opening. In order to improve the efficiency of the quantitative analysis processing, there has also been proposed a chemical analysis apparatus wherein a plurality of the slide housing compartments are disposed side by side, and the read-out head is constituted for movement along the housing compartments.
However, with the chemical analysis apparatus provided with the incubator as mentioned above, air readily flows through the read-out opening formed in the slide housing compartment, and therefore the temperature in the slide housing compartment readily fluctuates in the course of incubation. As a result, the temperature of the chemical analysis slide fluctuates, and the predetermined conditions of incubation cannot be satisfied. Therefore, the accuracy of quantitative analysis is deteriorated.
One approach to elimination of the aforesaid problems is to house the incubator in a temperature-controlled chamber. However, the temperature-controlled chamber for housing a large incubator provided with a plurality of the slide housing compartments as mentioned above becomes large. In this case, even though the control is carried out for maintaining the temperature in the temperature-controlled chamber at a predetermined value, the temperature in the temperature-controlled chamber becomes uneven, the predetermined conditions of incubation cannot be satisfied at some positions in the temperature-controlled chamber, and therefore the accuracy of quantitative analysis is deteriorated.